The present invention relates to a radiation-sterilized medical device. More particularly, the present invention relates to a packaged medical device provided with a deodorizing means adapted to prevent emanation of an odor upon withdrawal of a radiation-sterilized medical device from a sterile containment bag.
As a method for sterilizing medical devices, sterilization with gamma-rays has been widely employed in recent years, particularly in the field of disposable medical devices. In order to maintain sterility up till the time of use, such a disposable medical device is generally sealed in a sterile bag and then sterilized with gamma-rays as pre-packaged in the bag. However, because of the presence of oxygen in the bag, irradiation with gamma-rays or other radiation excites the oxygen to yield ozone, an allotrope of oxygen, and, hence, generates the so-called gamma odor which is considered to be associated with ozone. This odor emanating upon unsealing of the sterile bag for removal of the medical device therefrom gives an uncomfortable sensation to the user of the device.
Furthermore, disposable medical devices are made, for the most part, of some plastic material or other and may suffer from decreased strength due to oxidation with time. Particularly in dry radiation-sterilization in a gaseous atmosphere where the surface of the plastic material is exposed to air, the presence of radiation-excited oxygen promotes oxidation of the plastic material with time at elevated temperature so as to induce a decrease in strength.
In view of the problems mentioned hereinbefore, the present inventors conducted an intensive research and discovered that these problems all spring out from the presence of oxygen. Accordingly, they sought for means for elimination of oxygen.
The object of the present invention is to provide a dry radiation-sterilized medical equipment which does not give off an odor upon unsealing and is free from decreases in the strength of plastic parts thereof.
This and other objects of the invention will become apparent from the description hereinafter.